线虫内寄生真菌明尼苏达被毛孢(Hirsutella minnesotensis)的营养研究

Nutritional requirements of nematophagous fungus Hirsutella minnesotensis

明尼苏达被毛孢(Hirsutella minnesotensis)是中国大豆胞囊线虫重要的内寄生菌,本研究采取固体和液体2种培养方法测定了6种天然培养基、20种碳源、19种氮源和9种维生素对其生长、产孢和孢子萌发的影响。结果表明:H.minne-sotensis在酵母葡萄糖琼脂(Yeast dextrose agar,YDA)培养基上生长最快,在麦芽浸膏琼脂(Malt extract agar,MEA)培养基上产孢最好,胰化大豆琼脂(Tryptic soy agar,TSA)培养基既不适合生长,也不适合产孢。在碳氮源研究中,Melibiose在固体培养基上显著促进H.minnesotensis气生菌丝生长,Glycogen是液体培养和孢子萌发最好的碳源。H.minnesotensis在以Casein为氮源的培养基上气生菌丝最多,Peptone是H.minnesotensis液体培养最好的氮源,大多数的氮源可以促进H.minnesotensis孢子萌发,但L-Cystine抑制孢子萌发,且在固体培养中不能被H.minnesotensis利用。维生素对H.minneso-tensis的生长、产孢和孢子萌发有一定的促进作用。

Hirsutella minnesotensis is a parasite of second-stage juveniles of soybean cyst nematode, and has great potential in biocontrol. Six natural media were evaluated for growth and sporulation of 4 isolates of H. minnesotensis on agar. Meanwhile 20 carbohydrates, 19 nitrogen compounds and 9 vitamins were tested for growth, sporulation and spore germination of 3 isolates of H. minnesotensis on agar plates and in liquid cultures. In general, YDA was good for growth and MEA was good for sporulation, while TSA was not good for growth and sporulation of H. minnesotensis. Melibiose was the best carbon source for aerial mycelium growth on agar, and glycogen was the best carbon source for the growth in liquid culture and spore germination on agar. Casein and peptone was the best nitrogen source for aerial mycelium growth on agar and growth in liquid culture, respectively. Most of nitrogen compounds supported spore germination of H. minnesotensis except L-Cystine, it could not be utilized by any of the isolates on agar. Vitamins showed no significant effect on the growth, sporulation and spore germination of H. minnesotensis.